Monessen Hearth VWF30 User Manual

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27D8520 
9
Label all wires prior to disconnection 
when servicing controls. Wiring errors 
can cause improper and dangerous 
operation. Verify proper operation after 
servicing.
W
ARNING
Do not connect to 110 volt supply.
W
ARNING
Keep wiring away from heat 
source and hot surfaces. 
W
ARNING
THTP
TP
TH
Milli-volt 
Valve
Pilot
 WIRING (MILLI-VOLT)
Figure 7 - Wiring Diagram
The Milli-Volt (thermopile) is a self powered combination gas con-
trol that does not require 110VAC to operate. Refer to Figure 8 and 
installation instructions provided with optional wall switch or remote 
control for wiring instructions. A maximum length of 15 feet of 18awg 
two conductor wire is to be used for wall switch. Note switches must 
be suitable for millivolt operation. The optional wall switch must be 
mounted outside the firebox. The remote receiver location must not 
exceed a temperature of 120
“ F.
CHECKING SYSTEM OPERATION
The milli-volt system and individual components may be 
checked with a millivolt meter having a 0-1000MV range. 
Conduct each check shown in chart below by connection 
meter test leads to terminals as indicated.
A.  COMPLETE MILLI-VOLT SYSTEM CHECK 
("A" READING - CONTACTS CLOSED - CONTROL KNOB "ON" - MAIN BURNER SHOULD BE COME 
ON)
 
a.  If the reading is more than 100 millivolts and the automatic valve still does not come on - replace the control.
  b. If the closed circuit reading (“A” reading) is less than 100 millivolts, determine cause for low reading — 
proceed as follows:
B.  THERMOPILE OUTPUT READING CHECK 
(“B” READING - CONTACTS OPEN - MAIN BURNER OFF)
  a.  325 millivolts minimum. If the minimum millivolt reading is not obtainable, readjust pilot for maximum millivolt 
output. If millivolt reading is still below minimum specified, replace thermopile.
 
 
 CONNECT 
  
 
METER 
METER
  CHECK 
TO  
LEADS TO 
READING
 TEST 
TEST 
TERMINALS  SHOULD 
BE
 
COMPLETE 
TH & THTP 
Min. 100 mV
  
SYSTEM
 
THERMOPILE 
TP & THTP 
Min. 325 mV
  
OUTPUT  
Optional  Wall Switch 
or Remote Reciever
Switch